MEXICO CITY (AP) — Mexico said Friday that it seized 229 metric tons of precursor chemicals used to make methamphetamine, the third such huge seizure this month at the Pacific port of Lazaro Cardenas, all of which were bound for a port in Guatemala.

The seizure bringing to over 534 tons the amount of meth chemicals detected at Lazaro Cardenas in less than a month.

Authorities announced on Dec. 19 that they had found almost 100 metric tons of methylamine at the port, and earlier said that 205 tons of the chemical had been found there over several days in early December.

Experts familiar with meth production call it a huge amount of raw material, noting that under some production methods, precursor chemicals can yield about half their weight in uncut meth.

The Attorney General’s Office said the most recent seizure was found in 1,600 drums, and had been shipped from Shanghai, China.

All three shipments originated in China and were destined for Puerto Quetzal, Guatemala, authorities said.

The office has not indicated which cartels may have been moving the chemicals, but U.S. officials have noted that the Sinaloa cartel, Mexico’s most powerful, has moved into meth production on an industrial scale.

Sinaloa also has operations in Guatemala, and given recent busts by the Mexican army of huge meth processing facilities in Mexico, the gang may have decided to move some production to Guatemala.

Lazaro Cardenas is located in the western Michoacan state, which is dominated by the Knights Templar cartel and previously by the La Familia gang.

However, a series of arrests, deaths and infighting may have weakened those gangs’ ability to engage in massive meth production.

Also Friday, the attorney general’s office in the Gulf coast state of Veracruz reported that it had found ten bodies in an area along the border with the neighboring state of Tamaulipas. The office said investigators were alerted to the bodies by a tip, and are working to identify them and the cause of death.

The area has been the scene of bloody battles between the Gulf and Zetas cartels.